Turn to page 30 in the Airframe & Power plant Mechanics general handbook

Precise Measuring Tools

*These tools are very expensive and should be treated with care. * They can measure in very small increments quite precisely

Micrometer is defined : A Instrument used for measuring extremely small distances or an instrument for making precise linear measurements of dimensions such as diameters, thicknesses, and lengths of solid bodies; it consists of a C-shaped frame with a movable jaw operated by an integral screw

*In aviation this can be used for measuring the outside dia of many items. Hardware. Any and all engine parts, various other items on the aircraft. *The reason for the use of these tools is to ensure the proper tolerances are kept when inspecting or replacing parts . ATI's Inspection dept

*Manufacturers manuals will be full of dimensions that are to be used when inspecting. The tolerances are in place in part to ensure that proper fit will take place with mating parts *When choosing a micrometer you must be able to estimate the size that will be needed as the generally come in one inch increments. 0 to 1 ....1 to 2.......2to 3 and so on.

* The parts of a micrometer include the anvil spindle, sleeve and thimble. *Show the digital micrometer in the cabinet- how to change different anvils and why

Some of the most common occurrences of fraction-to-decimal conversions occur with the selection of twist drill sizes. A 0.125" hole is drilled using a 1/8" bit. A 0.250" hole is drilled using a1/4" bit. Some other common fractions are: ½ or 0.500 3/4 or 0.750 1 = 500 2 1000 125 ÷ 125 = 1 1000 ÷ 125 = 8

To turn any decimal to a fraction multiply it by the denominator you want Take 0.0625 and turn it into a 16th fraction by multiplying 0.0625 by 16................. And you get 1 which is the numerator or top number in a fraction, so the answer is 0.0625 = 1 16

Change the following decimals to fractions .125 to 8ths 1/8 .1875 to 16th 3/16 .4375 to 32nds 14/32

3 would be 3 ÷ 16 which would equal 0.1875 16 To turn any fraction to a decimal simply divide the numerator (top number ) by the denominator (bottom number) 3 would be 3 ÷ 16 which would equal 0.1875 16

Turn the following fractions into decimals 21/32 .65625 .6875 11/16 5/8 .625

Refer to page 30 of the general handbook What fraction is equal to 0.1875? What fraction is equal to 0.312? What decimal is equal to 3/8?

EVERYONE GET A MICROMETER AND SET IT TO READ THE FOLLOWING 0.429 0.609 0.014 0.148 0.366 0.911 0.783 0.272

CARRY OUT COMPONENT ID GET A SHEET OF PAPER AND PEN

Anvil , Barrel , Thimble , Lock Ring , Spindle , Frame

Vernier caliper- are also used for outside measuring Vernier caliper- are also used for outside measuring. Most dial calipers can also do inside measuring and the depth of a hole.

Click to see web site example of vernier caliper.....set to imperial

A digital protractor is used mainly to set the proper angles of a flight control . This can be done after a control has been changed or if the flight crew is complaining about a problem . By setting the control inline with the aircraft the protractor can be zeroed and then the stops can be set at the deflections as set by the manufacturer. **** 748 AILERON LOCKING STORY. Show them on the a/c how it works

Go through “what’s my angle” game , then all students try it up in the computer lab---------------------click Whats my angle

*A cable tensiometer is used to accurately measure the tension applied to an aircraft cable run. The tool come with different calibrated blocks to use with certain size cables. *The cables must be room temp as this will affect the readings. To obtain the proper cable tension the mechanic simply adjusts the turnbuckle to get the reading as laid out in the proper manuals.

Cylinder Bore Gauge are used in engine overhaul facilities

Machinists ruler

The End